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Oct. 20, 2009 (Philadelphia) -- The first in a new class of experimental drugs that targets the disease process involved in lupus beat out standard treatment in a large clinical trial, researchers say.

If the findings hold up, the drug, Benlysta, could become the first new drug for lupus in five decades.

About 1.5 million Americans have lupus, a complex disease in which the immune system attacks a person's own tissues, wreaking havoc on the joints, skin and other organs. Benlysta dampens the abnormal immune signals, calming down the immune system.

The new study involved 865 patients on standard therapy, including steroids, for lupus. One-third were also given a high dose of Benlysta, one-third a low dose, and one-third received a placebo.

Sandra V. Navarra, MD, head of rheumatology at the University of Santo Tomas, Manila, Philippines, reported the findings at the 73rd Annual Scientific Meeting of the American College of Rheumatology.

After one year, 58% of patients on high-dose Benlysta experienced a significant improvement in symptom severity, compared with just 43% of those on placebo.

Patients taking Benlysta also had fewer disease flare-ups, fewer severe flare-ups, and a longer time between flare-ups. They also reported less fatigue and better quality of life.

Previously reported findings from the study showed that the drug is also more effective at reducing pain, hair loss, and skin rash than placebo.

Of particular note, doctors say, was that more patients taking Benlysta were able to reduce their steroid dose. "One of the most important goals of treatment is to get patients off steroids, which cause so many unforgivable side effects -- bloating, weight gain, acne, high blood pressure, and others," says Joan T. Merrill, MD, medical director of the Lupus Foundation of America.

The most common adverse events were headache, muscle pain, upper respiratory tract infections, urinary tract infection, and influenza, and were comparable between the three treatment groups. Serious infections were reported by about 6% of patients in all three groups.

Human Genome Sciences Inc. and GlaxoSmithKline, which are developing the drug, funded the study.

Results of another large trial pitting Benlysta against standard care are scheduled to be released next month. If the drug works as well as in this study, the companies plan to apply for FDA approval of the drug.